1. Field of the Invention
The present invention relates to a thermosiphon for efficiently transferring heat by taking advantage of phase change in a working fluid.
2. Description of the Related Art
One of Conventional thermosiphons of this kind is disclosed in, for example, Japanese un-examined patent publication No. 2001-33139. The thermosiphon comprises a condensing section (a condenser) attached to a Stirling refrigerator (a refrigerator); and a circulation path consisting of a liquid line (a liquid pipe), an evaporator section (an evaporator) and a gas line (a gas pipe), said circulation path being connected to said condensing section.
Operating the Stirling refrigerator deprives the condensing section of heat to thereby condense a refrigerant (a working fluid) thereinside, then supplying the refrigerant thus condensed to the evaporator section via the liquid line so as to vaporize the fed refrigerant inside the evaporator section, thereby depriving a surrounding therearound of heat as a vaporizing latent heat, so that the heat around the evaporator section is transferred to the condensing section and further to the Stirling refrigerator by returning the vaporized refrigerant to the condensing section via the gas line.
For the above-mentioned condensing sections, those which are manufactured by machining metal ingots or by drawing metal plates have conventionally been known other than the one in the form of a coiled copper pipe as described in the above-mentioned patent publication. Further, for the above-mentioned evaporator sections, those which are manufactured by roll bond method or the like have been known besides the one in the form of a zigzagged copper pipe described in the above-mentioned publication.
According to the conventional thermosiphons, however, condensers formed by coiling a copper pipe have had a problem that it is difficult to keep such condensers in close contact with the refrigerators. Further, condensers manufactured by machining process or the like have had a problem that a high precision processing is necessary to keep such condensers in close contact with the refrigerators, thus resulting in high manufacturing costs.
On the other hand, evaporators formed of copper pipes have had a problem that as the cooling of the surroundings around the evaporators progresses, condensed working fluids are likely to stay inside the evaporators, thus leading to a possibility that circulation paths are clogged. Whilst evaporators manufactured by the roll bond method have had no problems as long as working fluids such as chlorofluorocarbon (CFC), alternatives to CFC or the like are used, they have had a problem that it eventually is impossible to use such evaporators as they are unable to withstand an inner pressure if other working fluid, such as carbon dioxide is used in line with no-CFC policy.